Cytokinesis in Pollen Mother Cells of Angiosperms, with Emphasis on Laurelia novae-zelandiae (Monimiaceae)

抄録

PMC cytokinesis in Laurelia novae-zelandiae is of a type apparently unique in the literature. Remnants of telophase I spindle fibres persist in reduced form during meiosis II and near the end of this division two phragmoplasts, linking ‘cousin’ nuclei, are formed in the region of the telophase I spindle fibres. It is not clear whether or not these secondary spindle fibres are the result of intensification and extension of the telophase I spindle remnants. Cytokinesis occurs by cell plate formation and the heterotypic cell plate is completed shortly before the homeotypic ones have completed their centrifugal growth. Variants of the two apparent basic types of cytokinesis are summarized and the question as to which is the more primitive in angiosperms is discussed.